Commands
The List Lines group of commands are no longer visible in the Code Assistant in the Code Editor (they will not appear when you type the first few characters), although they are still present in Studio 11 and will continue to function in legacy code. You can show these commands by disabling the appropriate Command Filter in the Modify menu in the Code Editor.
You should use the equivalent methods where available, such as $add() instead of Add line to list, to manipulate the contents of list variables.